1. Field of the Invention
The present invention relates to a method and apparatus for controlling electric power steering. More specifically, the present invention relates to a power steering control method and an apparatus for the same that can continually provide a steering assist force by using a motor in an electric power steering control apparatus even in cases where a torque sensor has broken down.
2. Description of the Prior Art
An electric power steering control method refers to a power steering control method that uses a steering assist force generator (for example, a motor) for assisting for a driver's steering force. For example, the electric power steering control method refers to a system that measures a driver's steering torque, calculates a steering assist force that corresponds to the steering torque, and provides the steering assist force by using a motor when the driver operates a steering wheel.
Such an electric power steering control method helps the driver perform the steering operation with little force, and provides various steering assist forces according to vehicle speeds to prevent an accident that may be caused by abrupt steering while driving at a high speed.
Accordingly, it is important to accurately measure a driver's steering torque in order to accurately control the power steering.
However, in cases where the reliability of a torque signal output from a torque sensor, which measures a driver's steering torque, is not ensured due to a breakdown in the torque sensor, power steering may be erroneously controlled, or power steering control itself may not be performed, which results in a serious traffic accident.
Despite these problems, the power steering control method in the related art abruptly stops supplying a steering assist force in the situation where a torque sensor has broken down, thereby causing a sense of difference in power steering and a failure to provide adequate time for the driver to counteract the breakdown. Further, in the case of the torque sensor breakdown, the power steering control method in the related art merely stops supplying the steering assist force and fails to propose a method for continually providing the steering assist force.